.header {
    height: 50px;
    background: -webkit-linear-gradient(left, #00d6ff, #008aff);
    /* Safari 5.1 - 6.0 */
    background: -o-linear-gradient(right, #00d6ff, #008aff);
    /* Opera 11.1 - 12.0 */
    background: -moz-linear-gradient(right, #00d6ff, #008aff);
    /* Firefox 3.6 - 15 */
    background: linear-gradient(to right, #00d6ff, #008aff);
    /* 标准的语法 */
    position: relative;
}
.header .title {
    height: 50px;
    line-height: 50px;
    text-align: center;
    font-size: 18px;
    color: white;
}

.header .left-btn {
    position: absolute;
    width: 60px;
    height: 50px;
    text-align: center;
    line-height: 50px;
    font-size: 18px;
    color: white;
}

.header .right-btn {
    position: absolute;
    width: 60px;
    height: 50px;
    right: 0;
    text-align: center;
    line-height: 50px;
    font-size: 18px;
    color: white;
}
.form .form-item {
    width: 300px;
    height: 50px;
    border-radius: 25px;
    background: #eaeaea;
    margin: 10px auto;
    position: relative;
}
.form .form-item .input {
    width: 200px;
    margin:auto;
    /* background:yellow; */
}
.form .form-item .input input {
    border:none;
    outline: none;
    background:none;
    width:100%;
    margin: 5px 0;
    height: 40px;
    font-size:18px;
    text-align: center;
}
.form .form-item .input input::placeholder {
    font-size: 16px;
    text-align: center;
}
.form .form-item .label {
    position: absolute;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    /* background:red; */
    left: 10px;
    top:50%;
    margin-top: -15px;
}

.btn:active {
    opacity: .7;
}

.hide {
    display: none;
}